Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Investigation of N,N,N-Trimethyl-L-alanyl-L-proline Betaine (TMAP) as a Biomarker of Kidney Function

Glomerular filtration rate (GFR) is the most widely used tool for the measurement of kidney function, but endogenous biomarkers such as cystatin C and creatinine have limitations. A previous metabolomic study revealed N,N,N-trimethyl-L-alanyl-L-proline betaine (TMAP) to be reflective of kidney function. In this study, we developed a quantitative LCMS assay for the measurement of TMAP and evaluated TMAP as a biomarker of GFR. An assay to measure TMAP was developed using liquid chromatography-mass spectrometry. After validation of the method, we applied it to plasma samples from three distinct kidney disease patient cohorts: nondialysis chronic kidney disease (CKD) patients, patients receiving peritoneal and hemodialysis, and living kidney donors. We investigated whether TMAP was conserved in other mammalian and nonmammalian species, by analyzing plasma samples from Wistar rats with diet-induced CKD and searching for putative matches to the m/z for TMAP and its known fragments in the raw sample data repository "Metabolomics Workbench". The assay can measure plasma TMAP at a lower limit of quantitation (100 ng/mL) with an interday precision and accuracy of 12.8 and 12.1%, respectively. In all three patient cohorts, TMAP concentrations are significantly higher in patients with CKD than in controls with a normal GFR. Further, TMAP concentrations are also elevated in rats with CKD and TMAP is present in the sap produced from Acer saccharum trees. TMAP concentration is inversely related to GFR suggesting that it is a marker of kidney function. TMAP is present in nonmammalian species suggesting that it is part of a biologically conserved process.

Hidden risks associated with conventional short intermittent hemodialysis: A call for action to mitigate cardiovascular risk and morbidity

The development of maintenance hemodialysis (HD) for end stage kidney disease patients is a success story that continues to save many lives. Nevertheless, intermittent renal replacement therapy is also a source of recurrent stress for patients. Conventional thrice weekly short HD is an imperfect treatment that only partially corrects uremic abnormalities, increases cardiovascular risk, and exacerbates disease burden. Altering cycles of fluid loading associated with cardiac stretching (interdialytic phase) and then fluid unloading (intradialytic phase) likely contribute to cardiac and vascular damage. This unphysiologic treatment profile combined with cyclic disturbances including osmotic and electrolytic shifts may contribute to morbidity in dialysis patients and augment the health burden of treatment. As such, HD patients are exposed to multiple stressors including cardiocirculatory, inflammatory, biologic, hypoxemic, and nutritional. This cascade of events can be termed the dialysis stress storm and sickness syndrome. Mitigating cardiovascular risk and morbidity associated with conventional intermittent HD appears to be a priority for improving patient experience and reducing disease burden. In this in-depth review, we summarize the hidden effects of intermittent HD therapy, and call for action to improve delivered HD and develop treatment schedules that are better tolerated and associated with fewer adverse effects.

A Paradigm to Discover Biomarkers Associated With Chronic Kidney Disease Progression

Biomarker discovery in the field of risk prediction in chronic kidney disease (CKD) embraces the prospect of improving our ability to risk stratify future adverse outcomes and thereby guide patient care in a new era of personalised medicine. However, many studies that report biomarkers predictive of CKD progression share a key methodological limitation: failure to characterise patients' renal progression precisely. This weakens any observable association between a biomarker and an outcome poorly defined by a patient's change in renal function over time. In this commentary, we discuss the need for a better approach in this research arena and describe a compelling strategy that has the advantage of offering robust and meaningful biomarker exploration relevant to CKD progression.

Helping people to live well with chronic kidney disease

Reduced glomerular filtration rate and presence of albuminuria are both associated with increased risk of several poor outcomes. People with chronic kidney disease also commonly suffer from lower quality of life than their age-matched peers. The experiences reported by patients with chronic kidney disease include being shocked by the diagnosis, being uncertain about the cause and worrying about progression and future treatment. Issues such as depression, pain and fatigue are common in people with chronic kidney disease. Helping people to live well with a long-term condition like chronic kidney disease should include efforts to reduce the risk of adverse events occurring in the future, and consider what can be done to enhance quality of life now. Clinicians can help by being aware of the patient perspective, communicating clearly and recommending interventions that reduce future risk as well as recognising and treating symptoms. Assessing overall treatment burden is an important component of management and non-pharmacological interventions that may improve mobility, strength and pain should be considered.

P1474IMPACT OF MALNUTRITION ON HEALTH-RELATED QUALITY OF LIFE IN DIALYSIS PATIENTS: A PROSPECTIVE STUDY

Background and Aims

Health-related quality of life (HRQoL) is severely impaired in dialysis patients compared to the general population. Previous studies have shown that malnutrition, a frequent complication and independent risk factor for mortality in the dialysis population, is associated with poor HRQoL. However, there is no published evidence regarding the impact of malnutrition on change in HRQoL over time. We sought to determine the most important predictors of poor HRQoL as well as the determinants of change in HRQoL over time in dialysis patients, with a particular focus on malnutrition.

Method

We enrolled 119 haemodialysis and 31 peritoneal dialysis patients in a 1-year single-centre prospective observational study. HRQoL was assessed using the physical and mental component scores (PCS and MCS, respectively) from the 36-Item Short Form Health Survey and the health state and visual analogue scores from the European Quality of Life 5-Dimensions (EQ5D) questionnaire. The 7-point scale Subjective Global Assessment (SGA) was performed to evaluate nutritional status. Energy, protein and fat intake, biochemical variables, anthropometric measurements and handgrip strength (HGS) were also measured. All study assessments were performed at baseline, 6 and 12 months.

Results

Mean age was 64±14 years. Malnutrition was present in 37% of the population (as determined by 7-point SGA). Patients with malnutrition and diabetes had significantly lower MCS, PCS and EQ5D scores compared to well-nourished and non-diabetic patients, respectively. At baseline, chronological age, serum albumin, energy and protein intake, and HGS correlated positively with PCS and EQ5D health state score. Multivariable analysis at baseline identified malnutrition as the strongest independent predictor of decreased HRQoL, after adjusting for confounders (Table 1). Patients who stayed or became malnourished during one year showed a significant decrease in MCS, PCS and EQ5D health state score at 12 months compared to baseline. This same group of patients had significantly lower MCS, PCS and EQ5D scores at baseline and 12 months compared to those who stayed or became well-nourished during one year. Prevalent/development of malnutrition was independently and significantly associated with the 1-year decrease in MCS and EQ5D health state score. In addition, a decrease in serum total protein and dietary protein intake (markers of malnutrition) were identified as independent determinants of 1-year decrease in MCS, PCS and EQ5D health state score.

Conclusion

We observed in this prospective observational study that presence of malnutrition was the most important and strongest independent predictor of decreased HRQoL in this dialysis population. Furthermore, prevalence/development of malnutrition and a decrease in markers of nutritional status were independently associated with a decrease in some HRQoL scores over 1 year. These findings strengthen the importance of undertaking screening to identify malnutrition, and providing specialised, individualised nutritional advice to all dialysis patients in order to prevent and/or improve nutritional status. Future studies with larger sample sizes, longer follow-up, and which include evaluation of barriers to effective nutritional interventions are needed to evaluate the impact of nutritional interventions on HRQoL and other long-term outcomes.

P0705MULTIPARAMETRIC RENAL MRI IN CHRONIC KIDNEY DISEASE: CHANGES IN CLINICAL AND MRI MEASURES OVER TWO YEARS

Background and Aims

Chronic kidney disease (CKD) progression is currently monitored using estimated GFR (eGFR) and albuminuria but these are relatively crude measures with multiple limitations. Multiparametric renal magnetic resonance imaging (MRI) combines several MR measures into a single scan session, offering the potential to assess severity, progression and response to therapy in CKD in a novel, non-invasive way. Previous studies have focussed on cross-sectional comparisons of MRI and clinical measures. In this study we sought to investigate the ability of MRI variables to predict and monitor progression of CKD over two years.

Method

Persons with CKD stage 3-4 (eGFR 15-59ml/min/1.732) who had undergone renal biopsy were recruited. Participants underwent multiparametric renal MRI scans on a 3T Philips Ingenia scanner at baseline, one and two years. In addition demographic data, medical history, eGFR and urine protein:creatinine ratio (uPCR) was collected. Multiparametric renal MRI comprised longitudinal relaxation time (T1 using SE-EPI and bFFE readouts), Diffusion Weighted Imaging, renal blood flow (Phase Contrast MRI), renal cortex perfusion (Arterial Spin Labelling), and Blood Oxygen Level Dependent (BOLD) relaxation rate (R2*). CKD progression was defined as participants having a slope in eGFR of -5ml/min/yr or greater over 2 years. Interstitial fibrosis was quantified on renal biopsy samples.

Results

22 participants underwent MRI scanning at baseline (7 participants were classified as ‘progressors’ and 15 as ‘stable’), while 13 completed all three scans (4 of whom were ‘progressors’). At baseline, cortex T1 was significantly higher for ‘progressors’ compared to ‘stable’ participants (p=0.02), and renal cortex perfusion was significantly lower (p=0.03). There was no significant difference in total kidney volume (TKV), ADC, renal cortex or medulla R2*, or renal biopsy measures of interstitial fibrosis between ‘progressor’ and ‘stable’ CKD participants.

At Year 1 and Year 2 compared to baseline, a decrease in total kidney volume (TKV) was found, with a significantly greater decrease in TKV in the ‘progressor’ group (p=0.04). Over time, T1 increased in the ‘progressor’ group versus baseline, particularly in the cortex which showed a significant difference at year 1 (p=0.034) and year 2 (p=0.053). There was a trend for a reduction in ADC in ‘progressors’ versus stable participants over time. There was no significant change over time or between groups in renal cortex perfusion, renal cortex or medulla T2*, or renal biopsy measures of interstitial fibrosis.

Conclusion

Our results show that at baseline lower renal cortex perfusion and higher renal cortex T1 were associated with progression of CKD over 2 years suggesting that these MRI parameters may be a predictors of progression. On the other hand, cortex T1, TKV and ADC changed more in ‘progressors’ than in ‘stable’ participants over time (TKV and ADC decreased, T1 increased), suggesting that they may be useful MRI measures to monitor progression. Further studies are required to confirm these findings in a larger cohort of patients before renal MRI can be recommended for clinical use.

P1078IMPACT OF A MEDIUM CUT-OFF DIALYZER ON SKIN AUTOFLUORESCENCE IN HAEMODIALYSIS PATIENTS

Background and Aims

Advanced glycation end-products (AGEs) are middle-sized uraemic toxins that accumulate in haemodialysis (HD) patients due to increased production, impaired excretion and insufficient removal. Previous studies have reported that the use of a medium cut-off (MCO) dialyzer promotes a greater removal of larger middle molecules (such as AGEs) than conventional high-flux HD and haemodiafiltration. However, to our knowledge, there is no published evidence regarding the effect of an MCO dialyzer on skin autofluorescence (SAF), a measure of long-term tissue AGE accumulation and independent risk factor for mortality in the HD population. We aimed to investigate the impact of using an MCO dialyzer on change in SAF over time in HD patients.

Method

HD patients were enrolled in a prospective observational study. SAF was measured using a validated Autofluorescence Reader at baseline, 12 and 24 months. During the initial 12 months patients dialysed using high-flux polysulphone, polyarylethersulfone or polyvinylpyrrolidone dialyzers. At a variable time after 12 months patients were switched to an MCO dialyzer (Theranova; Baxter®). Forty patients who had been using the MCO dialyzer for at least 3 months were included in this analysis.

Results

Mean age, baseline SAF levels and time on MCO dialyzer were 63±13 years, 3.5±0.9 arbitrary units (AU) and 124±49 days, respectively. SAF increased significantly from baseline to 12 months (3.5±0.9 vs. 3.9±1.1 AU; p&lt;0.0001) but tended to decrease between 12 and 24 months, after conversion to an MCO dialyzer (3.9±1.1 vs. 3.7±0.7 AU; p=0.06). Additionally, mean ΔSAF from baseline to 12 months was positive (0.41±0.68 AU) whereas ΔSAF from 12 to 24 months was negative (-0.18±0.76 AU; p=0.002 for comparison). Furthermore, SAF at 24 months correlated negatively and significantly with time on MCO dialyzer (r= -0.384; p=0.01) though second year ΔSAF (delta from 12 to 24 months) did not (r= 0.061; p=0.7).

Conclusion

We found in this observational study that SAF levels decreased/stabilised in HD patients after switching to an MCO dialyzer compared to the time when patients were using conventional high-flux HD and haemodiafiltration, during which SAF levels increased. Future prospective and interventional studies with larger sample sizes and longer follow-up are needed to confirm these findings and to evaluate the impact of using an MCO dialyzer on long-term outcomes, including survival.

P0269SYMPTOM-BURDEN IN PEOPLE LIVING WITH FRAILTY AND CHRONIC KIDNEY DISEASE

Background and Aims

Patients with chronic kidney disease (CKD) report high symptom-burden that adversely affects health-related quality of life (HRQOL). Frailty is an independent predictor of poor HRQOL in those with CKD.

Although there is a clear relationship between frailty and HRQOL in patients with CKD, the associated relationship with symptom experience is not well understood. Understanding how living with both frailty and CKD influences symptom-burden could inform management strategies that improve HRQOL of this vulnerable patient group. This study’s aim was to evaluate the symptom experience of patients living with frailty and CKD.

Methods

A total of 353 participants were recruited between February 2018 and October 2018 to this cross-sectional observational study. Participants completed physical activity (GP Physical Activity Questionnaire [GPPAQ]), cardiopulmonary fitness (Duke Activity Status Index, providing estimated VO2 peak), symptom-burden (Kidney Symptom Questionnaire [KSQ]) and HRQOL (Short Form 12 [SF-12]) questionnaires. Frailty was assessed using a modified Frailty Phenotype comprising 3 self-report components:

1) weakness/slowness defined as a SF-12 Physical Functioning score &lt;75; 2) low physical activity defined as ‘inactive’ by the GPPAQ; and 3) exhaustion defined as a SF-12 Vitality score &lt;55. Participants were categorised as frail if ≥2 components were present. Multiple imputation was performed for data considered to be either missing completely at random or missing at random. Regression analyses were used to assess the association between frailty, symptom-burden and HRQOL. Principal Component Analysis (PCA) was performed to explore symptom clusters experienced by non-frail and frail participants.

Results

Two hundred and twenty-five (64%) participants were categorised as frail. Frail participants were significantly older (77.7 vs. 71.5 years, p&lt;0.001) and had a significantly lower eGFR (45.8 vs. 50.9 mL/min/1.73m2, p&lt;0.001), albumin concentration (39.2 vs. 41.4 g/L, p&lt;0.001) and estimated VO2 peak (21.7 vs. 33.9 mL/kg/min, p&lt;0.001) than non-frail participants. Frailty, when adjusted for age, sex, eGFR and haemoglobin, was independently associated with higher KSQ total symptom score (p&lt;0.001) and lower SF-12 Physical Component Summary (PCS) and Mental Component Summary (MCS) scores (p&lt;0.001 and p=0.001, respectively). Lower eGFR was associated with higher KSQ total symptom score (p=0.004) and lower SF-12 PCS score (p=0.01). Frailty, when adjusted for age, sex, eGFR and haemoglobin, was independently associated with a two- to over five-fold increase in odds of experiencing all reported symptoms frequently, except loss of appetite and urinary frequency. Lower eGFR was only associated with increased odds of reporting frequent loss of muscle strength (p=0.04). PCA revealed two symptom clusters for non-frail participants and three symptom clusters for frail participants. Both non-frail and frail participants had symptom clusters associated with sleep disturbance and musculoskeletal symptoms. There was an additional unique symptom cluster (comprising loss of appetite, tiredness, feeling cold and poor concentration) experienced by frail participants.

Conclusion

Frailty is an independent predictor of high symptom-burden and poor HRQOL. Furthermore, symptom experience for people living with frailty and CKD is distinct from non-frail individuals, reporting a unique symptom cluster that may be a consequence of the frailty syndrome itself. This group of patients should be offered a holistic assessment so that problematic symptoms can be identified and addressed early before they impact more significantly on HRQOL. Future efforts should be focused on evaluating holistic models of care, such as the comprehensive geriatric assessment, for patients living with frailty and CKD.

Sodium and water handling during hemodialysis: new pathophysiologic insights and management approaches for improving outcomes in end-stage kidney disease

Space medicine and new technology such as magnetic resonance imaging of tissue sodium stores (²³NaMRI) have changed our understanding of human sodium homeostasis and pathophysiology. It has become evident that body sodium comprises 3 main components. Two compartments have been traditionally recognized, namely one that is circulating and systemically active via its osmotic action, and one slowly exchangeable pool located in the bones. The third, recently described pool represents sodium stored in skin and muscle interstitium, and it is implicated in cell and biologic activities via local hypertonicity and sodium clearance mechanisms. This in-depth review provides a comprehensive view on the pathophysiology and existing knowledge gaps of systemic hemodynamic and tissue sodium accumulation in dialysis patients. Furthermore, we discuss how the combination of novel technologies to quantitate tissue salt accumulation (e.g., ²³NaMRI) with devices to facilitate the precise attainment of a prescribed hemodialytic sodium mass balance (e.g., sodium and water balancing modules) will improve our therapeutic approach to sodium management in dialysis patients. While prospective studies are required, we think that these new diagnostic and sodium balancing tools will enhance our ability to pursue more personalized therapeutic interventions on sodium and water management, with the eventual goal of improving dialysis patient outcomes.

Effects of Sacubitril/Valsartan Versus Irbesartan in Patients With Chronic Kidney Disease

BACKGROUND

Sacubitril/valsartan reduces the risk of cardiovascular mortality among patients with heart failure with reduced ejection fraction, but its effects on kidney function and cardiac biomarkers in people with moderate to severe chronic kidney disease are unknown.

METHODS

The UK HARP-III trial (United Kingdom Heart and Renal Protection-III), a randomized double-blind trial, included 414 participants with an estimated glomerular filtration rate (GFR) 20 to 60 mL/min/1.73 m² who were randomly assigned to sacubitril/valsartan 97/103 mg twice daily versus irbesartan 300 mg once daily. The primary outcome was measured GFR at 12 months using ANCOVA with adjustment for each individual's baseline measured GFR. All analyses were by intention to treat.

RESULTS

In total, 207 participants were assigned to sacubitril/valsartan and 207 to irbesartan. Baseline measured GFR was 34.0 (SE, 0.8) and 34.7 (SE, 0.8) mL/min/1.73 m², respectively. At 12 months, there was no difference in measured GFR: 29.8 (SE 0.5) among those assigned sacubitril/valsartan versus 29.9 (SE, 0.5) mL/min/1.73 m² among those assigned irbesartan; difference, -0.1 (0.7) mL/min/1.73 m². Effects were similar in all prespecified subgroups. There was also no significant difference in estimated GFR at 3, 6, 9, or 12 months and no clear difference in urinary albumin:creatinine ratio between treatment arms (study average difference, -9%; 95% CI, -18 to 1). However, compared with irbesartan, allocation to sacubitril/valsartan reduced study average systolic and diastolic blood pressure by 5.4 (95% CI, 3.4-7.4) and 2.1 (95% CI, 1.0-3.3) mm Hg and levels of troponin I and N terminal of prohormone brain natriuretic peptide (tertiary end points) by 16% (95% CI, 8-23) and 18% (95% CI, 11-25), respectively. The incidence of serious adverse events (29.5% versus 28.5%; rate ratio, 1.07; 95% CI, 0.75-1.53), nonserious adverse reactions (36.7% versus 28.0%; rate ratio, 1.35; 95% CI, 0.96-1.90), and potassium ≥5.5 mmol/L (32% versus 24%, P=0.10) was not significantly different between randomized groups.

CONCLUSIONS

Over 12 months, sacubitril/valsartan has similar effects on kidney function and albuminuria to irbesartan, but it has the additional effect of lowering blood pressure and cardiac biomarkers in people with chronic kidney disease.

CLINICAL TRIAL REGISTRATION

URL: http://www.isrctn.com . Unique identifier: ISRCTN11958993.

Considerable international variation exists in blood pressure control and antihypertensive prescription patterns in chronic kidney disease

Although blood pressure control is a major goal in chronic kidney disease, no worldwide overview of either its achievement or antihypertensive prescriptions is currently available. To evaluate this we compared crude prevalence of uncontrolled blood pressure among 17 cohort studies, including 34 602 individuals with estimated glomerular filtration rate under 60 ml/min/1.73 m² and treated hypertension across four continents, and estimated observed to expected prevalence ratios, adjusted for potential confounders. Crude prevalence of blood pressure of 140/90 mm Hg or more varied from 28% to 61% and of blood pressure of 130/80 or more from 54% to 84%. Adjusted prevalence ratios indicated poorer hypertension control than expected in cohorts from European countries, India, and Uruguay, and better control in patients from North American and high-income Asian countries. Four antihypertensive drug classes or more were prescribed to more than 30% of participants in North American and some European cohorts, but this practice was less common elsewhere. Renin angiotensin-aldosterone system inhibitors were the most common antihypertensive drugs, prescribed for 54% to 91% of cohort participants. Differences for other drug classes were much stronger, ranging from 11% to 79% for diuretics, 22% to 70% for beta-blockers, and 27% to 75% for calcium-channel blockers. The confounders studied explain only a part of the international variation in blood pressure control among individuals with chronic kidney disease. Thus, considerable heterogeneity in prescription patterns worldwide calls for further investigation into the impact of different approaches on patient outcomes.

Clinical Practice Guideline on management of older patients with chronic kidney disease stage 3b or higher (eGFR<45 mL/min/1.73 m2): a summary document from the European Renal Best Practice Group

The population of patients with moderate and severe CKD is growing. Frail and older patients comprise an increasing proportion. Many studies still exclude this group, so the evidence base is limited. In 2013 the advisory board of ERBP initiated, in collaboration with European Union of Geriatric Medicine Societies (EUGMS), the development of a guideline on the management of older patients with CKD stage 3b or higher (eGFR >45 mL/min/1.73 m2). The full guideline has recently been published and is freely available online and on the website of ERBP (www.european-renal-best-practice.org). This paper summarises main recommendations of the guideline and their underlying rationales.

Multiparametric Renal Magnetic Resonance Imaging: Validation, Interventions, and Alterations in Chronic Kidney Disease

Background: This paper outlines a multiparametric renal MRI acquisition and analysis protocol to allow non-invasive assessment of hemodynamics (renal artery blood flow and perfusion), oxygenation (BOLD T₂^*), and microstructure (diffusion, T₁ mapping). Methods: We use our multiparametric renal MRI protocol to provide (1) a comprehensive set of MRI parameters [renal artery and vein blood flow, perfusion, T₁, T₂^*, diffusion (ADC, D, D^*, f_p), and total kidney volume] in a large cohort of healthy participants (127 participants with mean age of 41 ± 19 years) and show the MR field strength (1.5 T vs. 3 T) dependence of T₁ and T₂^* relaxation times; (2) the repeatability of multiparametric MRI measures in 11 healthy participants; (3) changes in MRI measures in response to hypercapnic and hyperoxic modulations in six healthy participants; and (4) pilot data showing the application of the multiparametric protocol in 11 patients with Chronic Kidney Disease (CKD). Results: Baseline measures were in-line with literature values, and as expected, T₁-values were longer at 3 T compared with 1.5 T, with increased T₁ corticomedullary differentiation at 3 T. Conversely, T₂^* was longer at 1.5 T. Inter-scan coefficients of variation (CoVs) of T₁ mapping and ADC were very good at <2.9%. Intra class correlations (ICCs) were high for cortex perfusion (0.801), cortex and medulla T₁ (0.848 and 0.997 using SE-EPI), and renal artery flow (0.844). In response to hypercapnia, a decrease in cortex T₂^* was observed, whilst no significant effect of hyperoxia on T₂^* was found. In CKD patients, renal artery and vein blood flow, and renal perfusion was lower than for healthy participants. Renal cortex and medulla T₁ was significantly higher in CKD patients compared to healthy participants, with corticomedullary T₁ differentiation reduced in CKD patients compared to healthy participants. No significant difference was found in renal T₂^*. Conclusions: Multiparametric MRI is a powerful technique for the assessment of changes in structure, hemodynamics, and oxygenation in a single scan session. This protocol provides the potential to assess the pathophysiological mechanisms in various etiologies of renal disease, and to assess the efficacy of drug treatments.

Hepatitis E virus infection and acute-on-chronic liver failure in West Africa: a case-control study from The Gambia

BACKGROUND

In sub-Saharan Africa, it is unknown whether hepatitis E virus (HEV) infection is a common precipitating event of acute-on-chronic liver failure (ACLF).

AIMS

To estimate the prevalence of HEV infection in general population and assess whether HEV is a common trigger of ACLF in cirrhotic patients in The Gambia, West Africa.

METHODS

We first conducted an HEV sero-survey in healthy volunteers. We then tested cirrhotic patients with ACLF (cases) and compensated cirrhosis (controls) for anti-HEV IgG as a marker of exposure to HEV, and anti-HEV IgA and HEV RNA as a marker of recent infection. We also described the characteristics and survival of the ACLF cases and controls.

RESULTS

In the healthy volunteers (n = 204), 13.7% (95% CI: 9.6-19.2) were positive for anti-HEV IgG, and none had positive HEV viraemia. After adjusting for age and sex, the following were associated with positive anti-HEV IgG: being a Christian, a farmer, drinking water from wells, handling pigs and eating pork. In 40 cases (median age: 45 years, 72.5% male) and 71 controls (39 years, 74.6% male), ≥70% were infected with hepatitis B virus. Although hepatitis B flare and sepsis were important precipitating events of ACLF, none had marker of acute HEV. ACLF cases had high (70.0%) 28-day mortality.

CONCLUSIONS

Hepatitis E virus infection is endemic in The Gambia, where both faecal-oral route (contaminated water) and zoonotic transmission (pigs/pork meat) may be important. However, acute HEV was not a common cause of acute-on-chronic liver failure in The Gambia.

Benefits of Aldosterone Receptor Antagonism in Chronic Kidney Disease (BARACK D) trial-a multi-centre, prospective, randomised, open, blinded end-point, 36-month study of 2,616 patients within primary care with stage 3b chronic kidney disease to compare the efficacy of spironolactone 25 mg once daily in addition to routine care on mortality and cardiovascular outcomes versus routine care alone: study protocol for a randomized controlled trial

BACKGROUND

Chronic kidney disease (CKD) is common and increasing in prevalence. Cardiovascular disease (CVD) is a major cause of morbidity and death in CKD, though of a different phenotype to the general CVD population. Few therapies have proved effective in modifying the increased CVD risk or rate of renal decline in CKD. There are accumulating data that aldosterone receptor antagonists (ARA) may offer cardio-protection and delay renal impairment in patients with the CV phenotype in CKD. The use of ARA in CKD has therefore been increasingly advocated. However, no large study of ARA with renal or CVD outcomes is underway.

METHODS

The study is a prospective randomised open blinded endpoint (PROBE) trial set in primary care where patients will mainly be identified by their GPs or from existing CKD lists. They will be invited if they have been formally diagnosed with CKD stage 3b or there is evidence of stage 3b CKD from blood results (eGFR 30-44 mL/min/1.73 m2) and fulfil the other inclusion/exclusion criteria. Patients will be randomised to either spironolactone 25 mg once daily in addition to routine care or routine care alone and followed-up for 36 months.

DISCUSSION

BARACK D is a PROBE trial to determine the effect of ARA on mortality and cardiovascular outcomes (onset or progression of CVD) in patients with stage 3b CKD.

TRIAL REGISTRATION

EudraCT: 2012-002672-13ISRTN: ISRCTN44522369.

Food intake increases liver stiffness measurements and hampers reliable values in patients with chronic hepatitis B and healthy controls: the PROLIFICA experience in The Gambia

BACKGROUND

By increasing the hepatic blood circulation, food intake has been suggested to increase liver stiffness measurement (LSM) values in HCV-infected patients.

AIM

To investigate prospectively the effects of food intake on LSM in hepatitis B virus (HBV)-infected patients and healthy controls.

METHODS

In The Gambia, patients included in the PROLIFICA project are screened for HBV at the community level and then invited for fasting assessment including LSM. Between April 2012 and October 2012, each day, the first five participants were invited to participate in this study. After the initial examination, a standardised 850 Kcal breakfast was provided. Effect of food intake was assessed by examining mean difference of LSM, IQR and IQR/LSM at T0 (fasting LSM1), T30min (LSM2) and T120min (LSM3) respectively.

RESULTS

A total of 209 subjects were enrolled in this study (133 were HBV positive, 76 healthy controls). Unreliable measurements occurred more frequently after food intake (5%, 24% and 18% at T0, T30min and T120min respectively). In both groups, median LSM2 was significantly higher than LSM1 [6.2 (IQR: 5.4, 7.9)] vs. 4.9 (4.2, 6.2), P < 0.0001. LSM3 was still higher than the baseline, but lower than LSM2. In multivariable analysis, no factor modified the effect of breakfast on LSM. In a subgroup of patients having liver biopsies, we confirmed that food intake can overestimate liver fibrosis.

CONCLUSIONS

Food intake significantly increases liver stiffness measurement and its IQR values in patients with chronic hepatitis B as well as healthy individuals; and also the number of unreliable liver stiffness measurement values.

Online measurement of haemoglobin concentration

BACKGROUND

Regular monitoring of haemoglobin in chronic haemodialysis patients is essential to ensure that targets for anaemia management are consistently achieved. Repeated blood sampling can be time consuming, invasive and, for pragmatic reasons, only infrequently performed, often delaying therapeutic change. On-line optical continuous monitoring of the haemoglobin concentration would allow non-invasive assessment of haemoglobin, and immediate therapeutic changes could be implemented, thereby improving the efficiency of anaemia management. This study aimed to evaluate the use of on-line haemoglobin concentration measurement.

METHODS

Eleven dialysis monitors (Integra Hospal) were calibrated using at least five haemoglobin samples spread over at least 4 g/dl. Optical measurement of haemoglobin concentration is already incorporated into the dialysis monitor to allow the study of relative blood volume. Fifteen patients were studied with paired haemoglobin measurements (i.e. dialysis monitor value and conventional laboratory assessment) taken at intervals over 7 months (mean 11.0+/-0.28 g/dl, range 7.5-14.8).

RESULTS

Haemoglobin measured by Hemoscan correlated well with the laboratory measurements (r2 = 0.83, P<0.0001), indicating that the machine values are broadly comparable with laboratory figures. There was a mean underestimate of haemoglobin by Hemoscan of 0.34%. There was no significant deterioration in the quality of this correlation over the study period (r2>0.8).

CONCLUSION

The ability of the dialysis monitor to measure the optical concentration of haemoglobin compared with conventional laboratory assessment is both precise and accurate. Regular on-line assessment of haemoglobin may allow more proactive micromanagement of renal anaemia, with a reduction in the time taken to achieve clinically important targets and give early warning of suboptimal response to treatment.

Locking of tunneled hemodialysis catheters with gentamicin and heparin

INTRODUCTION

Catheter-related infection (CRI) is a major cause of morbidity and mortality in patients receiving hemodialysis. Antibiotic locking of these catheters has been shown to increase both the success of systemic antibiotic treatment in line sepsis, and to reduce the incidence of sepsis. We have studied the use of gentamicin locking of catheters (in combination with standard heparin rather than previously reported citrate) to reduce CRI rates. Furthermore, we have investigated the effects of this strategy on epoetin requirements and vascular access function.

METHODS

Fifty patients were studied. Patients were randomized to catheter-restricted filling with either standard heparin (5000 IU/mL) alone, or gentamicin and heparin (5 mg/mL). Epoetin requirements and hemoglobin response were monitored over the study period.

RESULTS

The gentamicin-locked group suffered only one infective episode (0.3/1000 catheter days) compared to 10 episodes in six patients in the heparin alone group (4/1000 catheter days, P= 0.02). The isolated organisms were equally split between Staphylococcal species and coliforms. There were no statistically significant differences in delivered dialysis dose (Kt/V) or QA between the two groups. Use of antibiotic locking was associated with both a higher mean hemoglobin (10.1 +/-0.14 g/dL vs. 9.2 +/- 0.17 g/dL in the heparin group, P= 0.003) and a lower mean epoetin dose (9000 +/- 734 IU/week vs. 10790 +/-615 IU/week in the heparin group, P= 0.04).

CONCLUSION

The practice of locking newly inserted tunneled central venous catheters with gentamicin and heparin is an effective strategy to reduce line sepsis rates, and is associated with beneficial effects on epoetin requirements.

Anti-CD28 monoclonal antibody therapy prevents chronic rejection of renal allografts in rats

The effects of a signaling anti-CD28 mAb (JJ319), which interferes with the CD28-B7 T cell costimulation pathway thought to be involved in the development of chronic rejection of organ transplants, was investigated. Functional, morphologic, and molecular changes in rat renal allografts were examined up to 24 wk after placement. Control Lewis rats, recipients of F344 kidneys, received a single dose of a nonspecific mouse mAb intravenously on the day of transplantation (group 1). Group 2 animals were given anti-CD28 mAb in similar fashion. Group 3 animals were treated with a short course of cyclosporin A (CsA), and group 4 received both anti-CD 28 mAb and CsA. The majority (>95%) of animals in groups 2, 3, and 4 survived throughout the follow-up, compared with 28% in group 1 (P < 0.001). Group 2 and 4 recipients produced negligible proteinuria, whereas group 1 controls developed progressively increasing proteinuria after 4 wk and group 3 animals developed proteinuria by 24 wk. Allografts in groups 2 and 4 were morphologically unremarkable at 24 wk. Kidneys of group 1 animals rapidly developed changes of acute rejection, and those that survived long-term showed extensive glomerulosclerosis and interstitial fibrosis. Changes of early chronic rejection were noted in group 3 grafts. By reverse transcriptase-PCR, expression of representative inflammatory factors interferon-gamma and interleukin-10 were significantly elevated at 24 wk only in the surviving group 1 animals. A single dose of a signaling anti-CD28 mAb administered at transplantation or in combination with a short course of CsA significantly prolonged recipient survival, normalized function, and preserved the morphology of renal allografts in an established model of chronic rejection. These data support an important role for T cell costimulation in the evolution of the chronic process.

Activation of the heart by donor brain death accelerates acute rejection after transplantation

BACKGROUND

Donor brain death upregulates expression of inflammatory mediators in the heart. It is hypothesized that these nonspecific changes trigger and amplify acute rejection in unmodified recipients compared with hearts from normal living donors. We examined the inflammatory and immunological consequences of gradual-onset donor brain death on cardiac allografts after transplantation.

METHODS AND RESULTS

Functioning hearts were engrafted from normotensive donors after 6 hours of ventilatory support. Hearts from brain-dead rats (Fisher, F344) were rejected significantly earlier (mean+/-SD, 9. 3+/-0.6 days) by their (Lewis) recipients than hearts from living donor controls (11.6+/-0.7 days, P=0.03). The inflammatory response of such organs was accelerated, with rapid expression of cytokines, chemokines, and adhesion molecules and brisk infiltration of associated leukocyte populations. Upregulation of major histocompatibility class II antigens increased organ immunogenicity. Acute rejection evolved in hearts from brain-dead donors more intensely and at a significantly faster rate than in controls.

CONCLUSIONS

Donor brain death is deleterious to transplanted hearts. The resultant upregulation of inflammatory factors provokes host immune mechanisms and accelerates the acute rejection process in unmodified hosts.

IHG-2, a mesangial cell gene induced by high glucose, is human gremlin. Regulation by extracellular glucose concentration, cyclic mechanical strain, and transforming growth factor-beta1

We used cloning in silico coupled with polymerase chain reaction to demonstrate that IHG-2 is part of the 3'-untranslated region of gremlin, a member of the DAN family of secreted proteins that antagonize the bioactivities of members of the transforming growth factor (TGF)-beta superfamily. Mesangial cell gremlin mRNA levels were induced by high glucose, cyclic mechanical strain, and TGF-beta1 in vitro, and gremlin mRNA levels were elevated in the renal cortex of rats with streptozotocin-induced diabetic nephropathy in vivo. gremlin expression was observed in parallel with induction of bone morphogenetic protein-2 (BMP-2), a target for gremlin in models of cell differentiation. Together these data indicate that (a) IHG-2 is gremlin, (b) gremlin is expressed in diabetic nephropathy in vivo, (c) both glycemic and mechanical strain stimulate mesangial cell gremlin expression in vitro, (d) high glucose induces gremlin, in part, through TGFbeta-mediated pathways, and (e) Gremlin is a potential endogenous antagonist of BMPs within a diabetic glomerular milieu.

A randomised, double-blind comparison of the efficacy and safety of citalopram compared to mianserin in elderly, depressed patients with or without mild to moderate dementia

Depression is the most common psychiatric disorder among the elderly and in old age may interact with emotional and cognitive functioning. Depression in old age has been shown to be associated with degenerative changes in the brain. It is, therefore, important that in this patient population antidepressants with a favourable tolerability profile, such as the selective serotonin reuptake inhibitors (SSRIs), are examined for both antidepressant efficacy and effect on cognitive function and emotional impairment. This randomised, double-blind study compared the efficacy and tolerability of citalopram and mianserin in 336 elderly, depressed patients with or without dementia. Patients received either citalopram 20-40 mg/day or mianserin 30-60 mg/day for 12 weeks. The treatments were equivalent with respect to change in Montgomery-Asberg Depression Rating Scale (MADRS) total score; patients in both treatment groups responded well. Patients with dementia showed a smaller decrease in total MADRS score than patients without dementia. Both treatments were well tolerated with a relatively low incidence of adverse events. Fatigue and somnolence were more frequent with mianserin, while insomnia was more frequent with citalopram. Overall, this study showed that the two treatments were equivalent in efficacy, and that citalopram is an effective, well-tolerated and non-sedative treatment for elderly depressed patients with or without dementia.

Positive and negative effects of a child sexual abuse prevention program

This study evaluated a sexual abuse prevention program for sixth, seventh, and eighth graders ranging from 8 to 12 years of age. Six questionnaires concerning feelings of control, choice of protection strategy, perceived feasibility of refusing to cooperate with the intruder, appreciation of touch, school relationships, and social anxiety were used. Subjects were 161 children who participated in the program and a control group of 131 children. Results indicated short term overall effects of the program for the choice of safety strategies. Immediately after participation in the program the youngest and the oldest children felt less in control of an abusive interaction, the youngest pupils thought that refusal was less feasible but they appreciated physical touch more than before. These effects, however, were only of a short duration. In the long run children thought refusing more feasible and younger children showed less social anxiousness. As an unwanted side effect of the program the oldest children developed feelings of discomfort about being touched. Relationships with classmates and the teacher were not influenced by the intervention. It is suggested that the behavioral and attitudinal effects of the program could be ameliorated by extending the number or duration of the lessons.